TAR Terrestrial Arthropod Reviews 2 (2009) 129–147 brill.nl/tar Th e coff ee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae): a short review, with recent fi ndings and future research directions Fernando E. Vega 1, * , Francisco Infante2 , Alfredo Castillo2 and Juliana Jaramillo3,4 1 Sustainable Perennial Crops Laboratory, U. S. Department of Agriculture, Agricultural Research Service, Bldg. 001, BARC-W, Beltsville, MD 20705, USA 2 El Colegio de la Frontera Sur (ECOSUR), Carretera Antiguo Aeropuerto km 2.5, Tapachula, 30700 Chiapas, México 3 International Center of Insect Physiology and Ecology (ICIPE), P.O. Box 30772-00100, Nairobi, Kenya 4 Institute of Plant Diseases and Plant Protection, Leibniz Universität Hannover, Herrenhaeuser Str. 2, 30419 Hannover, Germany *Corresponding author; e-mail: [email protected] Received: 5 February 2009; accepted 26 March 2009 Summary Th e coff ee berry borer, Hypothenemus hampei (Ferrari), is the most devastating insect pest of coff ee throughout the world. Adult females bore a hole in the coff ee berry, where they deposit their eggs; upon hatching, larvae feed on the coff ee seeds inside the berry, thus reducing yield and quality of the marketable product. Th e insect spends most of its life inside the coff ee berry, making it extremely diffi cult to control. Th is paper presents a short review of the literature dealing with natural enemies of the coff ee berry borer, on the possible use of fungal endophytes as a biocontrol strategy, and on factors that might be involved in attracting the insect towards the coff ee plant. Th e paper identifi es some areas where research eff orts should be focused to increase the chances of successfully developing an eff ective pest management strategy against the coff ee berry borer. © Koninklijke Brill NV, Leiden, 2009 Keywords Biological control ; broca ; Coff ea ; Rubiaceae ; entomopathogens ; parasitoids ; predators ; Scolytinae Introduction Th e genus Coff ea (Rubiaceae) comprises 103 species (Davis et al., 2006 ), but only two of these are commercially traded: C. arabica L. and C. canephora Pierre ex A. Froehner (also referred colloquially to as “robusta”). Th e signifi cance of coff ee in the world econ- omy is staggering. It is grown in more than 10 million hectares in over 80 developing © Koninklijke Brill NV, Leiden, 2009 DOI 10.1163/187498209X12525675906031 130 F.E. Vega et al. / Terrestrial Arthropod Reviews 2 (2009) 129–147 countries ( http://faostat.fao.org/ ), and approximately 20 million families depend on this plant for their subsistence (Osorio, 2002 ; Gole et al., 2002 ; Vega et al., 2003 ; Lewin et al., 2004 ). Arabica coff ee has a lower caff eine level than robusta, and arabica is an allotetraploid (2n =4x =44), while robusta is a diploid (2n =22); furthermore, arabica coff ee grows best at high elevations, while robusta is grown at lower elevations (Wintgens, 2004 ; Vega 2008a ; Vega et al., 2008a ). Both species of Coff ea can either be grown at full sun, or under diff erent levels of shade (Muschler 2004 ; Perfecto et al., 2007 ). One of the major constraints to coff ee production throughout the world is the dam- age caused by the coff ee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae). Th is small beetle ( Figure 1 ) is endemic to Central Africa (Le Pelley, 1968 ), and can now be found throughout every coff ee-producing region, with the exception of Hawaii, Nepal, and Papua New Guinea. Adult females bore a hole in the coff ee berry and lay their eggs in internal galleries, with larvae feeding on the coff ee seed ( Figure 1 ). Feeding damage reduces yields, lowers the quality of the seed, and can result in the abscission of the berry. Th ere is a 10:1 female to male sex ratio, most likely due to the presence of Wolbachia (Vega et al., 2002 ), and once the insects moult into adults inside the berry, there is sibling mating, with the emerging females being already inseminated and ready to search for a berry in which they can start ovipositing. Th us, most of the life cycle is spent inside coff ee berries, making this cryptic insect quite dif- fi cult to control both by chemical and non-chemical strategies. Th e availability of artifi cial diets that allow for the production of thousands of speci- mens and multiple generations has made it possible to conduct research in the labora- tory (Villacorta and Barrera, 1993 ; Portilla and Streett, 2006 ). Recently, Jaramillo et al. ( 2009a ) developed a new technique that allows researchers to use infested-coff ee ber- ries in the laboratory for extended periods of time. In this paper, we present a concise review on the coff ee berry borer, focusing on biocontrol methods, and identify areas in need of research. Natural enemies Many natural enemies of the coff ee berry borer have been reported, including parasi- toids, predators, nematodes, and fungal entomopathogens (see below). Recent fi ndings serve to point out the many lacunae in the fi eld, and the need for innovative thinking. Parasitoids Th e fi rst coff ee berry borer parasitoid reported in the literature was the bethylid Prorops nasuta (Waterston) (Hargreaves, 1926 ). It can be found throughout most coff ee- producing countries in Africa (Le Pelley, 1968 ) and has been introduced to Latin America, the Caribbean, Oceania, and Asia (Klein-Koch et al., 1988 ; Barrera et al., 1990a ; Infante, 1998 ; Baker, 1999 ). Even though P. nasuta can be mass-reared using coff ee berry borer-infested coff ee berries (Abraham et al., 1990 ; Barrera et al., 1991 ; F.E. Vega et al. / Terrestrial Arthropod Reviews 2 (2009) 129–147 131 Figure 1. Female coff ee berry borer (A) walking over a coff ee seed (B) to show the small size of the insect (ca. 2 mm long, 1mm wide). Female coff ee berry borer boring a hole in a coff ee berry (C) with character- istic symptom of infestation revealing frass on the entrance hole (D). Damage caused by larval feeding inside the coff ee berry (E). Credits: (A) E. Erbe, USDA, ARS; (B) P. Greb, USDA, ARS; (C) and (E) G. Hoyos, Cenicafé; (D) G. Mercadier, USDA, ARS. 132 F.E. Vega et al. / Terrestrial Arthropod Reviews 2 (2009) 129–147 Infante et al., 2005 ), the results of introductions have not been promising due to a lack of establishment, problems with its production, or negligible parasitism rates (De Ingunza, 1964 ; Heinrich, 1965 ; Murphy and Moore, 1990 ; Ruales, 1997 ; Infante, 1998 ; Infante et al., 2001 ). Some recent and very interesting papers related to P. nasuta illustrate how much we still need to learn about coff ee berry borer parasitoids. For example, Chiu-Alvarado et al. ( 2009 ) have shown that P. nasuta is attracted to coff ee berry borer-infested coff ee berries, as well as to larvae/pupae and frass removed from the infested berries, but not to uninfested berries, or to larva/pupae and frass obtained from artifi cial diets. Th ese results indicate that an unidentifi ed attractant produced by the interaction between the insect and the berry is critical for P. nasuta to locate its host. Overall, the long- and short-range host location strategies of P. nasuta – as well as the other parasitoids men- tioned below - are poorly understood. Jaramillo et al. (2009b) showed that 97% of the P. nasuta collected in the fi eld origi- nate from berries collected on the ground, in contrast to 2.7% originating from berries on the tree. Th is is an important fi nding because it reveals that a common cultural practice in the Americas, involving the collection of berries on the ground to reduce coff ee berry borer levels (Bustillo et al. 1998 ), would also be removing an important biocontrol agent, i.e., P. nasuta . Jaramillo et al. (2009b) have suggested a screened enclosure that allows parasitoids to escape, but keeps the coff ee berry borer confi ned, to determine if this would increase parasitism levels in the fi eld. Another bethylid, Cephalonomia stephanoderis Betrem ( Figure 2 ), was discovered as a solitary larval and pupal ectoparasitoid of the coff ee berry borer in the Ivory Coast (Ticheler, 1961 ; Betrem, 1961 ), and has been reported in various coff ee-producing countries in western Africa (Koch, 1973 ; Damon, 1999 ; Barrera et al., 2000 ), but not in East Africa. In the Ivory Coast and Togo, C. stephanoderis can cause parasitism rates approaching 50% (Ticheler, 1961 ; Koch, 1973 ). Th is parasitoid can be mass-reared using coff ee berry borer-infested coff ee berries (Abraham et al., 1990 ; Barrera et al., 1991 ), and has been imported to more than 20 countries, and in most of these, it has become established (Klein-Koch, et al. 1988; Barrera et al., 1990a , 1990b , 2000 ; Bustillo et al., 1998 ; Baker, 1999 ), However, where follow-up studies have been con- ducted (e.g., Mexico and Colombia), the results have been disappointing (Barrera et al., 1990c ; Bustillo et al., 1998 ; Damon, 1999 ). Cephalonomia stephanoderis has been reported to produce a yet unidentifi ed marking pheromone after it oviposits on the coff ee berry borer (Barrera et al., 1994 ). Phymastichus coff ea LaSalle (Hymenoptera: Eulophidae; Figure 2 ) was discovered in Togo (Borbón-Martínez, 1989 ; LaSalle, 1990 ). It has been reported in many coff ee- producing countries in Africa (Lopez-Vaamonde and Moore, 1998), and has been introduced to many countries in Latin America (Baker, 1999 ) and to India, but there is to date no evidence that it has become established. Even though releases in Mexico resulted in relatively high levels of parasitism (up to 55%), it was not possible to recover the parasitoid 8-12 months after it was released (Galindo et al., 2002 ).